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Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)
POSIX allows mutexes to be recursive. That means the same thread can lock the same mutex twice and won't deadlock. Of course it also needs to unlock it twice, otherwise no other thread can obtain the mutex. Not all systems supporting pthreads also support recursive mutexes, but if they want to be P...
Getting the name of the currently executing method
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Thread.currentThread().getStackTrace() will usually contain the method you’re calling it from but there are pitfalls (see Javadoc):
Some virtual machines may, under some circumstances, omit one or more stack frames from the stack trace. In the extreme case, a virtua...
Inspect attached event handlers for any DOM element
...k= handler or HTML <element onclick="handler"> can be retrieved trivially from the element.onclick property from script or in-debugger.
Event handlers attached using DOM Level 2 Events addEventListener methods and IE's attachEvent cannot currently be retrieved from script at all. DOM Level 3 ...
What really is a deque in STL?
I was looking at STL containers and trying to figure what they really are (i.e. the data structure used), and the deque stopped me: I thought at first that it was a double linked list, which would allow insertion and deletion from both ends in constant time, but I am troubled by the promise made ...
Why use Object.prototype.hasOwnProperty.call(myObj, prop) instead of myObj.hasOwnProperty(prop)?
...y reference.
And since we are at it, why do we define this function at all?
See above.
Is it
just a question of shortcuts and local caching of property access for
(slight) performance gains...
It may make it quicker in theory, as the [[Prototype]] chain doesn't have to be followed, ...
Why should I use a pointer rather than the object itself?
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It's very unfortunate that you see dynamic allocation so often. That just shows how many bad C++ programmers there are.
In a sense, you have two questions bundled up into one. The first is when should we use dynamic allocation (using new)? The second is when should w...
Lambda function in list comprehensions
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The first one creates a single lambda function and calls it ten times.
The second one doesn't call the function. It creates 10 different lambda functions. It puts all of those in a list. To make it equivalent to the first you need:
[(lambda x: x*x)(x) for x in range(10)]
Or b...
Java JTable setting Column Width
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What happens if you call setMinWidth(400) on the last column instead of setPreferredWidth(400)?
In the JavaDoc for JTable, read the docs for doLayout() very carefully. Here are some choice bits:
When the method is called as a result of the ...
How to post data in PHP using file_get_contents?
...Sending an HTTP POST request using file_get_contents is not that hard, actually : as you guessed, you have to use the $context parameter.
There's an example given in the PHP manual, at this page : HTTP context options (quoting) :
$postdata = http_build_query(
array(
'var1' => 'some...
method of iterating over sqlalchemy model's defined columns?
...l exclude SA magic attributes, but will not exclude the relations. So basically it might load the dependencies, parents, children etc, which is definitely not desirable.
But it is actually much easier because if you inherit from Base, you have a __table__ attribute, so that you can do:
for c in Jo...